Consider the following extended argument:

Of course Martin Luther King, Jr., was a Liberal; for, he was if he believed the U.S.'s highest political priority should be equality, and he did. So, Martin Luther King, Jr., probably thought Capitalism was problematic, for he either thought that or he wasn't a liberal; and we've already established that he was a liberal.

But he wasn't a Communist. Because he believed that individuals should be allowed to own private property, and noone who believes that individuals should be allowed to own private property is a Communist. So, given that King was not a Communist, the F.B.I.'s J. Edgar Hoover should not have publicly portrayed King as a Communist. Since Hoover should have done it only if King was a Communist.